From 2935a0c47909cf964141a1feee5cd3c4721c2826 Mon Sep 17 00:00:00 2001 From: anon Date: Fri, 12 Mar 2021 11:59:06 +0000 Subject: [PATCH] async_protocol_handler_config: fix deadlock --- .../net/levin_protocol_handler_async.h | 52 +++++++++---------- 1 file changed, 24 insertions(+), 28 deletions(-) diff --git a/contrib/epee/include/net/levin_protocol_handler_async.h b/contrib/epee/include/net/levin_protocol_handler_async.h index f6b73a2d5..d062fa877 100644 --- a/contrib/epee/include/net/levin_protocol_handler_async.h +++ b/contrib/epee/include/net/levin_protocol_handler_async.h @@ -769,36 +769,32 @@ void async_protocol_handler_config::del_connection(async_p template void async_protocol_handler_config::delete_connections(size_t count, bool incoming) { - std::vector connections; + std::vector connections; + + auto scope_exit_handler = misc_utils::create_scope_leave_handler([&connections]{ + for (auto &aph: connections) + aph->finish_outer_call(); + }); + CRITICAL_REGION_BEGIN(m_connects_lock); for (auto& c: m_connects) { if (c.second->m_connection_context.m_is_income == incoming) - connections.push_back(c.first); + if (c.second->start_outer_call()) + connections.push_back(c.second); } // close random connections from the provided set // TODO or better just keep removing random elements (performance) unsigned seed = std::chrono::system_clock::now().time_since_epoch().count(); shuffle(connections.begin(), connections.end(), std::default_random_engine(seed)); - while (count > 0 && connections.size() > 0) - { - try - { - auto i = connections.end() - 1; - async_protocol_handler *conn = m_connects.at(*i); - m_connects.erase(*i); - conn->close(); - connections.erase(i); - } - catch (const std::out_of_range &e) - { - MWARNING("Connection not found in m_connects, continuing"); - } - --count; - } + for (size_t i = 0; i < connections.size() && i < count; ++i) + m_connects.erase(connections[i]->get_connection_id()); CRITICAL_REGION_END(); + + for (size_t i = 0; i < connections.size() && i < count; ++i) + connections[i]->close(); } //------------------------------------------------------------------------------------------ template @@ -860,18 +856,19 @@ int async_protocol_handler_config::invoke_async(int comman template template bool async_protocol_handler_config::foreach_connection(const callback_t &cb) { - CRITICAL_REGION_LOCAL(m_connects_lock); std::vector conn; - conn.reserve(m_connects.size()); auto scope_exit_handler = misc_utils::create_scope_leave_handler([&conn]{ for (auto &aph: conn) aph->finish_outer_call(); }); + CRITICAL_REGION_BEGIN(m_connects_lock); + conn.reserve(m_connects.size()); for (auto &e: m_connects) if (e.second->start_outer_call()) conn.push_back(e.second); + CRITICAL_REGION_END() for (auto &aph: conn) if (!cb(aph->get_context_ref())) @@ -883,11 +880,8 @@ bool async_protocol_handler_config::foreach_connection(con template template bool async_protocol_handler_config::for_connection(const boost::uuids::uuid &connection_id, const callback_t &cb) { - CRITICAL_REGION_LOCAL(m_connects_lock); - async_protocol_handler* aph = find_connection(connection_id); - if (!aph) - return false; - if (!aph->start_outer_call()) + async_protocol_handler* aph = nullptr; + if (find_and_lock_connection(connection_id, aph) != LEVIN_OK) return false; auto scope_exit_handler = misc_utils::create_scope_leave_handler( boost::bind(&async_protocol_handler::finish_outer_call, aph)); @@ -953,12 +947,14 @@ int async_protocol_handler_config::send(byte_slice message template bool async_protocol_handler_config::close(boost::uuids::uuid connection_id) { - CRITICAL_REGION_LOCAL(m_connects_lock); - async_protocol_handler* aph = find_connection(connection_id); - if (!aph) + async_protocol_handler* aph = nullptr; + if (find_and_lock_connection(connection_id, aph) != LEVIN_OK) return false; + auto scope_exit_handler = misc_utils::create_scope_leave_handler( + boost::bind(&async_protocol_handler::finish_outer_call, aph)); if (!aph->close()) return false; + CRITICAL_REGION_LOCAL(m_connects_lock); m_connects.erase(connection_id); return true; }